Switch



y 29, 1956 E. E. FORSTROM 2,748,205

SWITCH Dec. 14, 4 Sheets sheet l WITNESSES: INVENTOR Edward E.Forstrom4%. sf/MA. W 7

A'IITORNEY y 1956 E E FORSTROM 2,748,205

SWITCH Filed Dec. 14, 1951 4 Sheets-Sheet 2 Fig.2.

WITNESSES: INVENTOR ATTORNEY Edward E.Forstr0m.

May 29, 1956 E. FORSTROM SWITCH 4 Sheets-Sheet 3 Filed Dec. 14, 1951Fig.4.

INVENTOR Edward E.Forstrom.

ATTORNEY United States Patent F SWITCH Edward E. Forstrom, Bridgeport,Conn., assignor to The Bryant Electric Company, Bridgeport, Conn., acorporation of Connecticut Application December 14, 1951, Serial No.261,723

15 Claims. (Cl. 200--) This invention relates generally to electricswitches, and more specifically to multiple pushbutton switches.

For certain applications, such as for the control of surface units forelectric ranges, where a number of multiposition switches are requiredand only a relatively small space is available for mounting theswitches, it is necessary that the switches conform in size to theavailable mounting space and yet be capable of efficiently performing anumber of different switching operations, and at the same time becapable of segregation to be, identifiable with the respective devicescontrolled thereby.

One object of this invention, therefore, is to provide a novel type ofmultiple pushbutton switch which is small in size, yet is efiicient inoperation and capable of economical manufacture.

Another object of this invention is to provide a pushbutton switchconstruction wherein a plurality of pushbuttons are arranged in a circleand have novel interlocking means so that only one button may beoperated at a time.

Another object of this invention is to provide a switch having aplurality of pushbutton operating members with a novel cooperativearrangement of switches to be operated by the pushbuttons.

Still another object of this invention is to provide a switch of thetype described having a plurality of supply and load terminals and aplurality of pushbuttons and switches operated thereby, associated withsaid terminals in a novel manner.

These and other objects of this invention will become more apparent uponconsideration of the following de tailed description of preferredembodiments thereof, when taken in connection with the attached drawingsin which:

Figure 1 is a top plan view of a switch constructed in accordance withthis invention;

Fig. 2 is an enlarged transverse sectional view of the switch shown inFig. 1 taken substantially on the line iiH thereof;

Fig. 3 is an enlarged top view of the switch shown in Figs. 1 and 2 withthe cover and three of the pushbuttons removed;

Fig. 4 is also a top view of the switch shown in Figs. 1 to 3, beingsimilar to Fig. 3 except that all of the pushbuttons, and theirinterlocking means together with the base and movable contacts areremoved;

Fig. 5 is a side elevation view of the switch shown in. Figs. 1 and 2with a part of the side wall and coven being broken away and shown insection;

Fig. 6 is a view similar to Fig. 5, but shows a modified form ofpushbutton interlocking means;

Fig. 7 is a bottom view of one of the pushbuttons employed with theswitch shown'in Figs. 1 to 5;

Fig. 8 is a top view of one of the interlock membersemployed in theswitch illustrated in Figs. 1 to 5;

Fig. 9 is an elevation view looking at the inner side of the interlockmember shown in Fig. 8;

Fig. 10 is a top plan view of the base for the switch shown in Figs. 1to 5 taken substantially along the line X-X of Fig. 2;

Fig. 11 is a top view of one of the pushbuttons used in the modifiedform of switch shown in Fig. 6;

Fig. 12 is a cross-section view of the pushbutton shown in Fig. 11 takensubstantially on the line XIl-XH thereof;

Fig. 13 is a side elevation view of the pushbutton shown in Figs. 11 and12;

Fig. 14 is an elevation view of the roller which is employed with thepushbutton shown in Figs. 11 to 13;.

Fig. 15 is an elevation view looking at the inner side of an interlockmember employed in the switch shown in Fig. 6;

Fig. 16 is a bottom view of the interlock member shown in Fig. 15; and

Fig. 17 is a schematic view of the switch illustrating one circuit inwhich the switch may be employed.

The multiple pushbutton operated switch illustrated on the drawings andspecifically hereinafter described is specifically designed forcontrolling a pair of heating elements, such as the heating elementswhich are employed in the surface heating unit of an electric range.However, the invention is not limited to the control of these or otherheating units, nor it is limited to the precise number of switches orpushbutton operating members specifically disclosed herein. As thedescription proceeds, it will be apparent that a greater or lessernumber of pushbutton operating members and switch contacts to beoperated thereby may be employed while retaining important features ofthis invention, although as will be pointed out, the particular switchdescribed has certain novel features which are particularly adapted forthe control of heating units for electric ranges.

The specific switch shown on the drawings has eight: pushbuttonoperating members comprising an Off button and seven operating buttons Athrough G, with the latter being employed to operate switch contacts topro vide various degrees of heat from a multiple unit heating element,as will be described.

The switch shown on the drawings is enclosed within a switch casing 2,comprising a housing 4 adapted to be removably secured to a base 6, andwith the housing; having an open top adapted to be closed by a removablecover plate 8. The housing 4 and base 6 are preferably formed ofinsulating material such as molded insulating material, whereas thecover 8 may be a metal plate if desired. The base 6 has a plurality ofline and load terminals mounted on the bottom thereof, there beingthreeline terminals and three load terminals in the illustrativeembodiment of the invention herein particularly disclosed. At the innerside of base 6 there are mounted a plurality of movable switch contactswhich are adapted. to cooperate with stationary contacts mounted in the!housing 4. The housing 4 also carries the pushbutton operating membersand their interlocking means, together with a central indicating lamp72, and the cover 3 has a plurality of circularly spaced openings forreceiving the pushbutton operating members, respectively, and a centralopening for receiving a lens 88 through which light from the indicatinglamp is transmitted.

The housing 4 has an open top, as previously explained, and is formedinteriorly with a plurality of circumferentially spaced pushbuttonguideways it) for receiving each of the pushbutton operating members.Each pushbutton guideway 10 comprises an outer part 12 and an inner part14 separated by a circular track 16 on which the interlocking membersare adapted to be movably mounted, as will be hereinafter described.

The pushbutton operating members 18, 13 and 18 are preferably formed ofan insulating material, such as a molded insulating material, and forconvenience the 3% pushbuttons are labeled A, B, C, D, E, F, G and Oil.Each pushbutton includes an outer operating part 20 which is circular incross-section and an enlarged inner part which has a slot 22 of arcuateform disposed in the ll end thereof. Each pushbutton is adapted to resslot 22. a roller 24 which has a central pin ClV 111 ll 26 projectingfrom one side thereof to he received in a recess 23 formed at one sideof slot 22 and which extends longitudinally of each pushbutton apredetermined distance from the inner end thereof. Since the slot 22 ofeach pushbutton is only slightly wider than the thickness of a roller24, it will be apparent that the roller can have a substantial lateralmovement relative to the pushbutton limited only by engagement with thesides of recess 28 with roller pin 2s, and that the rollers are alsofreely movable longitudinally of each pushbutton throughout the lengthof the pushbutton slot 22 and can be assembled with the pushbutton bymerely dropping them into the slot 22 from the inner end of thepushbutton, with the roller pin 26 being received in recess 28.

it will be apparent from Fig. 7 of the drawing that the inner end ofeach pushbutton 18, 18' and 18" has a relatively wide portion 3G at theouter side of slot 22 which is adapted to be received in the outer part12 of a pushbutton guideway id, and the pushbutton has a relativelynarrow part 32 at the other side of notch 22 which is adapted to fitinto the inner part 14 of a pushbutton guideway iii. The inner ends ofthe bushbuttons are guided by the respective guideways lit forlongitudinal reciprocating movement of the pushbuttons to depressed andextended positions relative to the switch cover 8 by their relativelyclose sliding fit in the respective pushbutton guideways Till.

The rollers 24- of each pushbutton are adapted to cooperate withinterlock members 34 (Figs. 8 and 9) which are formed to be arcuate incross-section to correspond to the curvature of the circular track 16formed in the bottom of housing 4, and these interlock members have aflat bottom edge 36 which is adapted to seat on the housing track To tobe slidable along the track. The top of each interlock member 34 istapered upwardly substantially to a point as shown at 38, and areadapted to be assembled in the switch so that there is an interlockmember 34 located between adjacent rollers 24 of the pushbuttons, andwith portions of the interlock members e eived in slots 22 of thepushbuttons.

The switch shown in Figs. 1 to is illustrated at its off position withthe Oil pushbutton depressed. This has caused the roller 24 mounted inthe Off. pushbutton to move downwardly and separate the interlockmembers 34 at opposite sides thereof. This causes the interlock members34 to be forced into close proximity with each other except for the twoin engagement with the roller 24 of the Oil pushbutton, to thus forcethe rollers 24 of all of the other buttons outwardly by their engagementbetween the upper tapered portions 38 of adjacent interlock members 34(Fig. 5), and thus cause all of the other buttons A to G to move totheir extended positions. in the event any of the other pushbuttons atlocations A to G are depressed, it will cause the two interlock members34 in contact with its roller 24 to be separated circumferentially andthus force these interlock members into engagement with all the rest toultimately take up the space between the interlock members contactingthe roller of the Oil pushbutton and force the latter outwardly. Thewidth of interlock members 34 and diameter of rollers 24 are so arrangedthat but a single pushbutton may be depressed at one time, anddepression of any given pushbutton causes all the remainder of thepushbuttons to assume their extended positions, and prevents depressionof the other buttons so long as the aforesaid one is held depressed. Thearrangement described above thus forms an effective interlock betweenthe pushbuttons which permits but a single pushbutton to be depressed atany given time, and causes 4 movement of all the remaining pushbuttonsto extended positions whenever any one of them is depressed.

Reciprocating movement of the pushbuttons 18, 18 and 18 is utilized tooperate switches, and except for the switch operated by the Offpushbutton, parts of each switch are mounted in the housing 4, and otherlatter outwardly. The width of interlock members 34 illustrative form ofthe invention herein specifically disclosed, a switch is provided ateach of the inner and outer sides of each of the operating pushbuttonsat locations A to G, with the stationary contacts of these switchesbeing mounted in the housing 4, and the movable contacts thereof beingmounted on the base 6.

For supporting the stationary switch contacts, the housing 4 is providedwith a relatively short arcuate terminal strip as which spanspushbuttons E, F and G, and

a longer arcuate terminal strip 42 which spans operating pushbuttons A,B, C and D and the Off pushbutton. These arcuate terminal strips 40 and42 are located adjacent the outer periphery of housing 4 close to theopen side thereof, being supported on a plurality of spaced ledges 44which may be formed integral with the casing, and are located betweeneach of the pushbuttons and form part of the pushbutton guideways It Thearcuate terminal strips 40 and 42 may be secured in fixed position byany desired means, for example, as by screws 46 which secure theterminal strips directly to the ledges 44, and by connecting screws 48which will be hereafter more particularly described.

Each of the pushbutton guideways 10 has a notch 59 extending outwardlythereof for substantially the entire depth of housing 4, and theterminal strips 40 and 42 having integral spaced tongues 52 which dependfrom the inner edges thereof into the notches for supporting contactbuttons 54, which face outwardly and form stationary switch contacts.

A centrally located terminal disc 56 is carried by the housing adjacentthe open side thereof, and this disc has integral downwardly extendingtongues 58 located opposite each of the pushbuttons except the (35"pushbutton 18', with these tongues having contact buttons 60 mountedthereon and facing inwardly of a notch 62 provided at the inner side ofeach pushbutton iidcway ltl, except the guideway id for the Off pushbuttn. The terminal disc 56 has a central opening 64- and is adapted to besecured in position by a screw 65 which extends through an openingprovided in the housing in a nunuer to be hereinafter referred to.

The housing 4 has a central opening 68 aligned with the central opening64 in terminal disc 55, and this opening there is mounted a contactsleeve 7% which is provided with a suitable means, such as a bayonetslot, for receiving an indicating lamp in a manner to make 1.. contactwith the terminal sleeve of the lamp and hold the lamp with its centralterminal in engagement with a resilient conducting strip 76 centrallydisposed at the inner end of central opening 63 of housing 4. Theresilient conducting strip 76 which makes contact to the central lampterminal extends to the inner side of housing 4 where it is bent toextend along the base of the housing and be secured to the inner end ofa resilient switch blade 78 having a contact button 89 at the outer endthereof located opposite the fixed contact 5'4 which is adjacent the Oilpushbutton. The resilient conducting strip 7'6 is secured in engagementwith the inner end of switch blade '73 and they are both secured to thebottom of housing 4 by any desired securing terms, such as by a rivet82. The contact sleeve 74 for toe indicating lain p is connected by aconductor as which extends out of the central opening es of housing 4-and across the bottom of the housing to the securing screw do with whichit electrically connected, and is thereby electrically counccb ed withthe arcuate terminal strip 4i). The conductor 84 for the indicating lampmay include a resistor 86 to limit current flowing through the lamp.

grasses The cover 8 for the housing 4 is provided with a central openingin which a cup-shaped lens 88 may be threadedly mounted to fit over theouter end of lamp 72. The openings 90 for the pushbuttons arecircumferentially spaced about the central opening in cover plate 8, forfreely slidably receiving the operating portions of the pushbuttons. Thecover may be removably secured in place in any desired way, for example,as by screws 92 threaded into housing 4.

The base 6 of the switch carries a plurality of line terminals, therebeing three in the illustrative embodiment of the invention comprisingline terminals 594 and 18 and a line neutral terminal 96. The lineterminal 14 is electrically connected to the arcuate terminal strip 42adjacent the open side of housing 4 by the screw 48 which extendsthrough the housing and carries a nut which holds terminal 94- in placeat the underside of the base 6 in an appropriately formed groove in thematerial of the base. The neutral line terminal 96 is electricallyconnected with the arcuate terminal strip 41) in a similar way, namely,by the screw 48 cooperating with terminal strip and extending throughhousing 4 and having a nut in engagement with terminal 96 at theunderside at base 6 to hold it in position on the base 6. The other lineterminal 98 is held in position and electrically connected to theterminal disc 56 near the open end of housing 4 by the screw 66 whichextends from terminal disc 56 through a bore provided in housing a andhas a nut at its outer end which engages terminal 98 to hold it in placeon base 6. The screws 48 and 66 thus serve not only to electricallyconnect their associated terminals and terminal strips, but also assistin securing the terminal strips 40 and 42 and terminal disc 56 to thehousing and at the same time secure the terminals to the housing base,

as well as holding the base 6 and housing 4 in assembled relation.

As previously mentioned, the movable contacts of each of the switchesexcept the one for the Olf pushbutton are carried by the base 6, and byreference to Figs. 2 and 10 of the drawing, it will be observed thatthese movable contacts are carried by switch blades formed of aresilient conducting material such as a copper alloy, and comprise anouter row circularly spaced blades 160, and an inner circularly arrangedrow of spaced blades 1412. Each of the switch blades 160 and 162 aresecured at their inner end to a terminal strip mounted at the inner sideof the base which will be hereinafter specifically described, by asuitable securing means such as a rivet 104 or the like. The switchblades 1% and 162 are then substantially reverse-1y bent at an acuteangle as at 1116, and their outer portions then continue outwardly as at168 in a direction substantially at right angles to the base 6, beingprovided with an angularly bent cam follower portion 116 adjacent theirouter ends, and with an extreme outer end offset contact portioncarrying a contact button 112 and 113 mounted so as to face the adjacentpushbutton and stationary contact. The outer and inner sides of eachpushbutton may be formed with a cam surface 114 which is engageable withthe cam follower portion 110 of an adjacent switch blade 1116 or 162 tocam the switch blade away from its opposed stationary contact 54 or 68,as the case may be, when the pushbutton is at an outer extendedposition. When a pushbutton is depressed, the switch blades may moveinwardly so that their contact buttons 112 and 113 engage theirrespective stationary contacts. Preferably, the blades 1% and 162 aremounted on the base 6 so that their normal bias is into engagement withthe fixed contacts to close the circuit. A contributing factor to thebias of switch blades 161) and 102 to their closed circuit positions isthe cooperation of these blades with the openings 161 provided in thebottom wall of housing 4 for individually receiving the blades when thebase 6 and housing 4 are assembled together. These openings are adaptedto engage the blade in the vicinity of inner blade portions 106 and 1613to form, in effect,

a fulcrum for bending of the blades when the upper por' tions are movedto open circuit positions by the cam portions 114 of the respectivepushbuttons, thus relieving the extreme inner part of the blades fromsubstantial bending stress and confining the bending stress to the partof each blade 160, 162 to the portion thereof ex tending from a point atthe bottom wall of housing 4 outwardly to the free end thereof.

The switch base 6 also carries a number of load terminals, there beingthree in the illustrative embodiment of the invention, for connection(Fig. 17) to a two-part heating element X, Y. As illustrated, the loadterminal 116 is adapted for connection to one end of one part Y of theload resistance, the load terminal 118 is adapted to be secured to oneend of the other part X of the load resistance, and the load terminal120 is adapted to be connected in common to the remaining ends of thetwo parts X and Y of the load resistance. At the upper face of base 6,there is a terminal disc 122 secured thereto, as by a bolt 124 whichpasses through the base in contact with the terminal disc 122 and withterminal 118 to thereby electrically connect terminal 118 with theterminal disc 122, as well as mechanically secure these parts to thebase 6. A terminal strip 126 having offset arcuate portions is alsomounted on the inner surface of base 6, being secured thereto by asecuring screw 12% and a connecting screw 130 which extends through thebase 6 and serves to mount the terminal 121? on the rear of base 6 andelectrically connect it and terminal strip 126. A second terminal strip132 having offset arcuate portions is also mounted at the inner side ofbase 6, being secured thereto by a plurality of securing screws 134 andby a connecting screw 136 which extends through the base 6 and loadterminal 116 to secure these parts to the base and electrically connectthem.

It will be noted that each of the pushbuttons except the Off pushbutton18' operates its movable switch blades 160, 102 to open the circuit whenthe pushbutton is at an extended position, and permits its switch blades100 and 102 to close the circuit when the pushbutton is at a depressedposition. The Off pushbutton 16 has but a single switch blade 78 locatedat the outer side of this button, and a single cam portion 135 isprovided on the Off pushbutton which opens the switch blade 78 y, whenthe pushbutton is depressed, and permits it to move to closed circuitposition when the Off pushbutton is at an extended position.Accordingly, it will be apparent that all of the switches are openedwhen the Off pushbutton is depressed.

Referring now to the schematic showing of this switch and the circuitwith which it may be used shown in Fig. 17 of the drawings, it will beapparent that when the pushbutton A is depressed, it will cause the Oilpushbutton to move to an extended position which will cause its movablecontact 80 to engage stationary contact 54 and thus establish a circuitfrom line conductor L2, through terminal 94 of the switch, terminalstrip 42, the closed contacts 54 and 81) of the switch operated by theOff pushbutton, lamp 72, resistance 36, terminal strip 40, and switchterminal 96, to the neutral line conductor, thus energizing theindicating lamp at a voltage of 110 volts, assuming the supply currentto be one which supplies 220 volts between conductors L1 and L2, and 110volts between either of conductors L1 or L2 and N. At the same time,depression of pushbutton 18 closes the movable contacts 112 andstationary contacts 54, as well as movable contact 113 and stationarycontact 60 at location A. In this regard, it will be noted that thereare two outer contacts 54 at location A and pushbutton 18" has two outercam surfaces 114 for operating the two outer switch blades 160, so thatwith the three switches at this location closed, a circuit will beestablished from supply conductor L2 to terminal 94 of the switch, andthrough terminal strip 42 and the upper outside contacts 54, 112 asviewed in Fig. 17, to terminal strip 132, load terminal 116, and thefree end of resistance Y. The circuit may then be traced throughresistance Y to load terminal 120 of the switch, terminal strip 126, theinner contacts H3, oil at location A, terminal strip 56 and lineterminal 93 to line conductor Ll, thus subiecting resistor Y to 220volts. The free end of resistance X is connected to load terminal 118 ofthe switch and to terminal disc 122, through the lower outside contacts112, 54, thence by way of terminal strip 42, and line terminal 94 toline conductor L2, to thereby also subject the resistor X to 220 volts.Accordingly, depres sion of push button it; at location A acts toconnect resistors X and Y in parallel across a 220 volt circuit.

Depression of the pushbuttons at locations 13 and C connect the resisors Y and X, respectively, across supply conductors Ll and L2 as will beapparent, and depression of the pushbutton at location D acts toconnect. resistors X and Y in series across supply conductors Ll and L2.

epression of the pnshbuttons at locations E, F and G act to connectresistor X, Y and X and Y in series, respcctively, across a lit) voltcircuit. Thus, tracing the circuit which is established when thepushbutton at location E is depressed, it will he observed, that thecircuit extends from supply conductor N to line terminal 95 of theswitch, then by way of terminal strip 4%), the outer contacts 54, 12 atlocation E, terminal strip 126, and load terminal of the switch to thecommon connection of resistors X and Y. From there the circuit proceedsthrough resistor Y to load terminal 116 of the switch, terminal strip132, the contacts 113, 60 at location E to terminal strip 56 and lineterminal 98 of the switch, to supply conductor Ll, to thereby subjectresistor X to llO volts.

it can thus be seen that if resistors X and Y are made to be of unequalvalue, they will be connected singly or in combination in various waysso that each of the seven diiierent operative positions of the switchprovide seven different wattages, and thus seven diiferent degrees ofthe heat from the resistors X and Y. Moreover, when each of thepushbuttons at the seven operative positions A through G are depressed,the Gil pushbutton is at an extended position to energize the circuitfor the indicating lamp to thus provide an indication that one or bothof the resistors are energized. The indicating lamp '72 is extinguishedonly when the Oil pushbutton is depressed to thus indicate that neitherof resistors X and Y are energized.

A modified form of interlocking means is illustrated in Fig. 6, withcertain details thereof shown in Figs. 11 to 16. This type of interlockis similar to that previously disclosed in that the switch haspushbuttons 138 adapted to operate switches (not shown) by cam portions13) thereof in the same manner as the pushbuttons 1S previouslydescribed. The pushbuttons 138 also have slots Ml} extending into theirinner ends which are curved in conformity with the curvature provided bycircular track for slidabiy supporting interlock members. However, theslot i l-9 at the inner end of each pushbutton 338 has a top wall withinclined ends 142, and outer side 146 of the material of the pushbuttonforming slot 140 is longer than the inner side 144, and each of thesesides have formed therein opposed slots 148 for receiving central pintleparts 159 of rollers 152, the rollers 152 thus have substantially nomovement longitudinally of a pushbutton 135: but are permitted to movelaterally thereof along the lengths of slots 14-8.

The pushbutton rollers 152 are adapted to cooperate with interlockmembers 154 which are transversely curved to conform to the curvature ofthe circular track on which these interlock members are adapted toslide. Opposite ends of each interlock member are tapered upwardly as at15c and $58, with one end 156 being formed with a notch loll, and theopposite end being formed with a tongue lZ of reduced thickness which isadapted 8 to fit into the notch 16% of the interlock member adjacentthereto.

The advantage of the interlocking arrangement for the pushbuttons shownin Figs. 6 and ll to 16 is that the individual interlock members 154-have essentially tongue (E62) and groove (loll) interfitting parts sothat there can be no substantial relative lateral movement of theinterlock members 154 while permitting ree edge-wise movement in acircular path in conform nee with the circular track formed in theswitch housing similar to the train the embodiment of. invention shownin Figs. l to 5. In all other respects, the interlock function is thesame in the embodiment of the invention shown in Figs. 6 and ll to 16,in that when one of the pushbuttons is depressed, it separates the twointerlock members 154 with v tell its roller i522 engages, and thusmoves the r members more closely adjacent each other to force therollers of the other pushbuttons upwardly and cause such otherpushbuttons to move to an extended position.

Having described preferred embodiments of the invention in accordancewith the patent statutes, it is desired that the invention be notlimited to the specific for is thereof herein specifically disclosedbecause it will be obvious that switches constructed in accordance withthis invention may be used for the control of loads other thanresistance heating loads, the number of pushbuttons may be varied, anddifferent types of interlocking provisions rnay be employed with thesame arrangement for the pushbutton operation of switches. it will alsobe apparent that other features of the invention, will also have certainnovel features of cooperation with the illustrative embodiment of theinvention herein specifically described, may also be useful apart fromthis specific switch or be useful w' h other types of switches. Such afeature is the assembly feature of this invention, namely, the separatebase and housing, having terminals and portions of switches mounted onthe base, and having pushbutton operating members and the remainingparts of the switches mounted in the housing, to provide separatesubassemblies which may be merely brought together and assembled bymeans which both mechanically and electrically connect the separate baseand housing units comprising tie switch according to one aspect of thisinvention. Accordingly, it is desired that this invention be interpretedas broadly as possible and that it be limited only as required by theprior art.

I claim as my invention:

1. A switch comprising, a vitch casing, a plurality oi? pushbuttonoperating members projecting through openings in one wall or" saidcasing, resocctively, a plurality of switches mounted in said casingeach of which includes a stationary contact and a movable contact, therebeing at least one switch for each pushbutton. means on each pushbuttonfor operating the movable contact of its switch in response topush'outton movement, a plurality of cam members slidably mounted insaid casing in a direction substantially at right angles to the movementof said pushbuttons and located at the inner ends of said pushbuttons,rollers mounted on the inner ends or said pushbuttons by a connectionhaving lost motion in the direction of the sliding movement of sai cammembers to permit both rotational movement and translator-y movement ofthe rollers in the direction of siding movement of said cam member andeach of said rollers being located between adjacent cam members so as tobe engageable therewith and to cause sliding movement thereof inopposite directions upon depression of its associated pushbutton andthereby to cause elevation of the other pushbuttons.

2. A switch comprising, a plurality of pushiuttcn operating members, aplurality of switches mounted in said casing each or which includes astationary contact and a movable contact, there being least one switchfor each pushbutton, means on each pushbutton for operating sweat themovable contact of its switch in response to movement of the pushbutton,a plurality of cam members slidably mounted in a direztion substantiallyat right angles to the movement of said pushbuttons and located at theinner ends of said pushbuttons, the inner ends of said bushbuttons beingslotted, a roller mounted in the slot of each pushbutton by a connectionhaving lost motion in the direction of the sliding movement of said cammembers to permit both rotational movement and translatory movement ofthe rollers in the direction of the sliding movement of said cammembers, and each of said rollers being located between adjacent cammembers so as to be engageable therewith and to cause sliding movementthereof in opposite directions upon depression of its associatedpushbutton and thereby to cause elevation of the other pushbuttons.

3. A switch comprising, a plurality of pushbutton operating membersarranged substantially in a circle, a plurality of switches each ofwhich includes a stationary contact and a movable contact, there beingat least one switch for each pushbutton, means on each pushbutton foroperating the movable contact of its switch in response to movement ofthe pushbutton, a plurality of curved cam members slidably mounted in acircular direction substantially at right angles to the movement of saidpushbuttons and located at the inner ends of said pushbuttons, the innerends of said pushbuttons being slotted, a roller mounted in the slot ofeach pushbutton by a connection having lost motion in the direction ofthe sliding movement of said cam members to permit both for rotationalmovement and translatory movement of the rollers in the direction of thesliding movement of said cam members, and each of said rollers beinglocated between adjacent cam members so as to be engageable therewithand to cause sliding movement thereof in opposite directions upondepression of its associated pushbutton and thereby to cause elevationof the other pushbuttons.

4. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, said cam members having slidably interfitting tongue andgroove portions which extend in the direction of sliding movement ofsaid cam members, said tongue and groove portions being of an extent toremain in interfitting engagement throughout the extent of movement ofsaid cam members, rollers rotatably mounted on the inner ends of saidpushbuttons, and each of said rollers being engageable with at least oneof the adjacent cam members to cause sliding movement thereof upondepression of its associated pushbutton and to thereby cause elevationof the other pushbuttons.

5. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, said cam members having slidably interfitting tongue andgroove portions which extend in the direction of sliding movement ofsaid cam members, said tongue and groove portions being of an extent toremain in interfitting engagement throughout the extent of movement ofsaid cam members, rollers mounted on the inner ends of said pushbuttonsby a connection having lost motion in the direction of the slidingmovement of said cam members to permit both rotational movement andtrans- 1G latory movement in the direction of the sliding movement ofsaid cam members, and each of said rollers being located betweenadjacent cam members so as to be engageable therewith and to causesliding movement thereof in opposite directions upon depression of itsassociated pushbutton and thereby to cause elevation of the otherpushbuttons.

6. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direaction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, the inner ends of said pushbuttons being slotted, a rollermounted in the slot of each pushbutton for rotational movement,projection and recess means on said roller and at least one side of saidslot, respectively, permitting limited translatory movement of therollers in the direction of the sliding movement of said cam members,and each of said rollers being located between adjacent cam members soas to be engageable therewith and to cause sliding movement thereof inopposite directions upon depression of its associated pushbutton and tothereby cause elevation of the other pushbuttons.

7. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, the inner ends of said pushbuttons being slotted, a rollermounted in the slot of each pushbutton, each roller having pintleportions at opposite sides slidably received in grooves provided inopposite sides of its push button slot which extend in the direction ofmovement of said cam members to permit both rotation and translatorymovement of the rollers in the direction of the sliding movement of saidcam members, and each of said rollers being located between adjacent cammembers so as to be engageable therewith and to cause sliding movementthereof in opposite directions upon depression of its associatedpushbutton and to thereby cause elevation of the other pushbuttons.

8. A switch comprising, a switch casing including an enclosure and aseparable base, a plurality of pushbutton operating members slidablymounted in said enclosure and projecting through openings in one wallthereof, a plurality of switches mounted in said casing and eachincluding relatively fixed and movable contacts, a plurality of line andload terminals on said base, one contact of each switch also beingmounted on said base to be separable therewith and with said terminalsas a unit from said enclosure and said pushbutton operating members, thebottom of said enclosure to which said. base is secured being open topermit access of the interior of the enclosure to the contact carried bythe base, said base being solid to close the bottom of said enclosurewhen assembled therewith, at least one of said switches for eachpushbutton with the movable contact thereof located adjacent one side ofits pushbutton when said base and enclosure are secured together, atleast one other contact of each switch being secured to and mountedwithin said enclosure so as to be cooperable with said one contact ofeach switch, means on the aforesaid one side of each pushbutton foroperating the movable contact of its switch in response to movement ofthe pushbutton, and means in said enclosure mechanically engageable bysaid pushbuttons for interlocking them so that their operationisconfined to a predetermined mode.

9. A switch comprising, a switch casing including an enclosure and aseparable base, a plurality of pushbutton operating members slidablymounted in said enclosure and projecting through openings in one wallthereof, a plurality of switches mounted in said casing and eachincluding relatively fixed and movable contacts, a plurality of line andload terminals mounted on said base, the movable contact of each switchalso being mounted on said base to be separable therewith and with said.terminals as a unit from said enclosure and said ushbutton operatingmembers, the bottom of said onclosure to which said base is securedbeing open to permit access to the interior of the enclosure by themovable contacts carried by the base, said base being solid to close thebottom of said enclosure when assembled therewith, at least one of saidswitches for each pushbutton with (is movable contact thereof locatedadjacent one side of its pushbutton when said base and enclosure aresecured together, at least one fixed contact of each switch beingsecured to and mounted within said enclosure so as to be cooper-ablewith said movable contact of each switch, means on the aforesaid oneside of each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, and means in said enclosuremechanically engageable by said pushbuttons for interlocking them sothat their operation is confined to a predetermined mode.

if). A switch comprising, a switch casing, a plurality of pushbuttonoperating members arranged substantially a circle and projecting throughopenings in one wall of casing, respectively, a plurality of switchesmounted n said casing, there being at least one switch for eachpushbutton, means operable by movement of each pushuttor; for operatingits switch, each pushbutton except one causing the contacts of itsswitch to open when the pushbnttons are elevated and closed when thepushbuttons depressed, a signal light mounted in said casing behind acentral opening in said one casing wall and electrically connected inseries circuit with the switch of said one pushbutton the contacts ofwhich are open when said one pushbutton is depressed and closed when itis elevated, a. light transmitting member secured to said cover so as toextend over said central opening whereby said signal light transmitslight theret'hrough beyond said cover when energized, and interlockingmeans in said casing for permitting only one of said pushbuttons to bedepressed at a time.

ll. A switch comprising, a switch casing, a plurality u hbnttonoperating members arranged substantially "e and projecting throughopenings in one wall of n: respectively, a plurality of switches mountedthere being at least two switches for each pi: except one, meansoperable by movement of each pushbutton. for operating its switches,each pushbutton except the said one causing the contacts of its switchesto open when the pushbuttons are elevated and closed when thepushbnttons are depressed, a signal light mounted in said casing behinda central opening in said one casing wall and electrically connected inseries circuit with the switch of said one pushbutton the contacts ofwhich are open when said one pushbutton is depressed and closed when itis elevated, and interlocking means in said casing for permitting onlyone of said pushbuttons to be de ressed at a time.

12. A switch comprising, a switch casing, a plurality of operatingpushbuttons and an 011" pushbutton projecting through spaced openingsarranged in a circle in one wall of said casing, respectively, switchesmounted in said casing at the inner and outer sides of said circle,there being switches at both inner and outer sides of each operatingpushbutton for operation thereby, a plurnlity of line and load terminalsfor said casing, means electrically connecting one of said lineterminals to one contact of each of the inner switches, the othercontacts thereof being connected to said load terminals, respectively,means electrically connecting others of said line and load terminals tothe contacts of each of the outside switches, respectively, meansresponsive to depression of each of the operating pushbuttons forclosing its switches and for opening its switches when the pushbutton isextended, and interlocking means in said casing for permitting only oneof said pushbuttons to be depressed at a time.

7 13. A switch comprising, a switch casing, a plurality of operatingpushbuttons and an if pushbutton projecting through spaced openingsarranged in a circle in one wall of said casing, respectively, switchesmounted in said casing at the inner and outer sides of said circle,there being switches at both inner and outer sides of each operatingpushbutton for operation thereby, three line terminals, one of which isa neutral terminal, and three load terminals for said casing, meanselectrically connecting one of said line terminals to one contact ofeach of the inner switches, the other contacts thereof being connectedto said load terminals, respectively, means electrically connecting onecontact of some of the outer switches to the neutral terminal, with theother contacts of said some outer switches being electrically connectedto two of said load terminals, respectively, the remainder of said outerswitches having one contact thereof electrically connected to theremaining line terminal and the other contacts thereof electricallyconnected with said load terminals, respectively, means responsive todepression of each of the operating pushbuttons for closing its switchesand for opening its switches when the pushbutton is extended, andinterlocking means in said casing for permitting only one of saidpushbuttons to be depressed at a time.

14. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, said cam members having slidably interfitting tongue andgroove portions which extend in the direction of sliding movement ofsaid cam members, said tongue and groove portions being of an extent toremain in interfitting engagement throughout the extent of movement ofsaid cam members, the inner ends of said pushbuttons being slotted inthe direction of the sliding movement of said cam members, a rollerrotatably mounted in said slot of each of said pushbuttons,respectively, each of said cam members having a portion thereof locatedwithin at least one of said slots of said pushbuttons at all times, andeach of said rollers being engageable with at least one of the adjacentcam members to cause sliding movement thereof upon depression of itsassociated pushbutton and to thereby cause elevation of the otherpushbuttons.

15. A switch comprising, a plurality of pushbutton operating members, aplurality of switches each of which includes a stationary contact and amovable contact, there being at least one switch for each pushbutton,means on each pushbutton for operating the movable contact of its switchin response to movement of the pushbutton, a plurality of cam membersslidably mounted in a direction substantially at right angles to themovement of said pushbuttons and located at the inner ends of saidpushbuttons, each of said cam members having a tongue portion at one endand a groove portion at its other end which portions extend in thedirection of sliding movement of said cam members and which are slidablyinterfitting with said tongue and groove portions on the other of saidcam members, said tongue and groove portions on interfitting cam memberseach having opposed sloping cam surfaces, rollers rotatably mounted onthe inner ends of said pushbuttons and each of said rollers 13 beingengageable with at least one of said opposed cam 2,442,766 surfaces tocause sliding movement of one of said cam 2,475,237 members upondepression of its associated pushbutton 2,529,374 and thereby to causeelevation of the other pushbuttons. 2,531,457

5 References Cited in the file of this patent 603 ,924 UNITED STATESPATENTS 607,670

Smith July 2, 1918 Andrews Dec. 2, 1947 10 14 Garvin June 8, 1948 GordonJuly 5, 1949 Caruso Nov. 7, 1950 McLarn Nov. 28, 1950 FOREIGN PATENTSGreat Britain June 25, 1948 Great Britain Sept. 2, 1948

